AWS Lambda lets you run code without provisioning or managing servers. The advantage of using Lamdba is: zero administration. Just upload your code and Lambda takes care of everything required to run and scale your code with high availability. So how does one deploy a flask application to AWS Lamdba.

Enter Zappa

From their github site: “Zappa makes it super easy to deploy all Python WSGI applications on AWS Lambda + API Gateway. Think of it as “serverless” web hosting for your Python web apps. That means infinite scaling, zero downtime, zero maintenance - and at a fraction of the cost of your current deployments!”

So let’s get started:

1) Go to the directory containing the flask code.

2) Setup your virtual env

$ pip install virtualenv                     ###only if you dont have virtualenv already installed
$ virtualenv env
$ source env/bin/activate
$ pip install flask zappa

This will create a zappa_setting.json file which should look something like the one below. Make sure the s3_bucket matches the one you have access to. Dev stands for your dev environment, you can have as many configurations as you like.

{ "dev": {
        "s3_bucket": "your_s3_bucket",
        "app_function": "";

3) Install AWS CLI and enter your access key and secret access key. These can be obtained via the AWS console. Create one if you dont have one already.

$ pip install awscli
$ aws configure

4) Run

$ zappa deploy dev
That's it. Your app should be running on AWS Lambda!